According to sources close to the situation, Microsoft CEO Steve Ballmer is working on what is likely to turn into a significant restructuring of the massive software company, which could also move several current execs to more prominent roles. Sources noted that the changes — which center on solidifying Microsoft into the “devices and services company” that Ballmer wrote about in his annual shareholder letter last October — are still being worked out, and could still change substantively. But, noted several people close to the situation, the new configuration could include larger roles for several execs, including Satya Nadella, president of its Servers and Tools division; Tony Bates, president of its Skype communications division; and Don Mattrick, president of its Interactive Entertainment division. How their new and perhaps expanded roles and those of others in top management will shake out is unclear.